Impacts of Heavy Metals on Aquatic Dwellers: A Literature Review

Heavy metals are one of the key contaminants and pollutants of the aquatic ecosystem, that are not only posing a life threat to aquatic dwellers, but also they are of a serious concern for human health. Humans are at risk because man depends on aquatic resources for food and medicines. Although heavy metals can be naturally released into the aquatic environment, their presence is majorly attributed to anthropogenic activities such as the indiscriminate disposal of household and industrial wastes, mining, fertilizer, and pesticide application. Heavy metals are metals that are greater than 5 g/cm3 in density and additionally, highly soluble and persist in the environment for a long period of time, and therefore easily accumulate in a food chain. Due to the close contact between aquatic organisms and water bodies, aquatic organisms easily take up heavy metals in dissolved form. Therefore, this paper reveals different kinds of aquatic dwellers, the ecological risk assessment and the toxicity effects of heavy metals in aquatic ecosystems. Furthermore, the bioaccumulation of heavy metals on man as a final consumer was discussed and the affected body organs were revealed. Finally, there are discussions on some the bioindicators of heavy metals and their remediation from the aquatic environment.